I think it is more than just self votes or even whale votes; I have been noticing that a lot of minnows have been vandalising the "buy a vote" system by spamming "borrowed" content (i.e. single YouTube post) and then get the system to vote for them.
I do not mind the voting system if people are not so money hungry enough to spam the site with junk and try to create a value out of it.
It's like throwing an original product "advertisement" and tries to sell it as an actual product.
If you get what I mean.